A Display device including a display panel such as a liquid crystal panel is used for portable electronic devices such as mobile phones, smartphones, and notebook computers. Such a display device includes a display panel including a display panel having a display portion displaying images, and semiconductor ships that drive the display panel by processing input signals from a signal supply source and generating output signals and supplying the output signals to the display portion. In such a display device that is classified as a small-to-medium size, the semiconductor chips may be preferably mounted by the chip-on-glass (COG) mounting method in that the semiconductor chips are directly mounted in an area of the display panel other than a display portion. An example of an apparatus of manufacturing such a display device is described in Patent Document 1.